He then spent a year in Los Angeles on a Fulbright scholarship carrying out postdoctoral research on ethnomusicology at UCLA as well as studying composition with Elaine Barkin.
As of 2015 he remains an adjunct professor of music in the Southern Cross University School of Arts and Social Sciences.
He first became interested in Sculthorpe's piano compositions while still a high school student in New South Wales and decided to write his final year music essay on the composer, which according to musicologist Graeme Skinner proved to be "the most thorough and perceptive analysis of Scunthorpe's output to date [1967]".
[6] Hannan's own compositions explore tonal as well as polytonal, and atonal techniques and are often leavened with humour, e.g., the radiophonic works Alphabeat and Slonimsky Variations and Beespeak and Cat's Night Out for trumpet and digital manipulation.
His 2003 Burning Questions, a radiophonic work commissioned by ABC Radio National included the sounds of a burning baby grand piano, the observers' reactions, and Hannan playing Beethoven's Moonlight Sonata on the piano prior to setting it alight.